The present invention relates to locking devices, and can be used in particular for constricting devices for body parts, such as a vein constrictor.
Devices of the above mentioned general type are known in the art. One of such devices is disclosed in my U.S. Pat. No. 5,314,437. It has an elastic band to form a loop around the body part to be constricted. When the band is tightened by pulling of its free end, the force which occurs at the end connected to a housing of the device turns the clamping rocker to its clamping position in which it arrests the band in its constricting condition.
In the device disclosed in my patent when a pressure is applied to convert the device into a closed position, a cap connected with one end of the band is snapped into a housing of the device. After the use of the device, when a pressure is applied to the clamping rocker, it turns so that its clamping edge releases the band, and the band due to the restoring force can slide automatically to release the band. At the same time, a further turning movement of the clamping rocker under the action of the pressure applied in the same direction leads to opening of an arresting closure, or in other words removal of the cap from the housing.
This construction has however the disadvantage that by operating the clamping rocker exclusively, the release of the band and the opening of the closure are performed simultaneously and very fast, so that the cap with the band can “jump” from a remaining part of the device, thus causing uneasiness for a user.